KR20180035204A - Fixing device - Google Patents

Abstract

The present invention provides a mounting device including: a tubular flexible rotating body rotating while being in contact with a recording material on which an image is formed; and an inner surface facing unit facing the inner surface of the rotating body at an end portion in the direction of the busbar of the rotating body. The inner surface facing unit moves toward the upstream in the carrying direction of the recording material in accordance with the lateral movement in the direction of the busbar of the rotating body, and thus restricts the lateral movement of the rotating body.

Description

FIXING DEVICE

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device having a tubular flexible rotating body and fixing an image formed on a recording material to a recording material.

In a fixing device mounted on an image forming apparatus using an electrophotographic recording system and using a flexible rotating body, there is a problem that the rotating body moves laterally in the direction of the bus bar during rotation of the rotating body. A regulating member for regulating the lateral movement of the rotating body is often provided at a position opposite to the end face of the rotating body in order to regulate this lateral movement. Japanese Patent Laying-Open No. 2011-248285 discloses a fixing device having such a regulating member.

However, recent image forming apparatuses are required to have higher speed and energy saving. With this demand, the rotational speed of the rotating body also increases, and the pressure applied to the end face of the rotating body when the rotating body contacts the lateral movement regulating member is increased. Further, in order to suppress the heat capacity of the rotating body, the thickness and diameter of the rotating body are reduced. As a result, the pressure per unit area applied to the end face of the rotor becomes large. In addition, recent image forming apparatuses have a demand for long life. This increases the time during which the rotor end face rubs against the lateral movement restricting member. As described above, as the performance required for the image forming apparatus is increased, the end face of the rotating body is apt to be cut, and the durability of the rotating body becomes insufficient. Therefore, there is an increasing demand for a mechanism for regulating the lateral movement of the rotating body.

SUMMARY OF THE INVENTION The present invention has been made in view of these problems, and an object of the present invention is to provide a fixing device capable of improving the durability of a flexible rotating body.

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a tubular flexible rotating body that rotates in contact with a recording material on which an image is formed; and a fixation member including an inner surface facing portion opposed to an inner surface of the rotating body, And the inner surface facing portion moves toward the upstream in the carrying direction of the recording material in accordance with the lateral movement in the direction of the bus bar of the rotating body.

According to a second aspect of the present invention, there is provided an image forming apparatus comprising: a tubular flexible rotating body rotating while contacting with a recording material on which an image is formed; and as a movable member opposed to an end surface of the rotating body in the direction of the busbar of the rotating body, There is provided a fixing device including a movable member including an inner surface opposed portion facing the inner surface of the rotating body at the entire end portion thereof and an end surface opposed portion facing the end surface of the rotating body, When the rotating body presses the end face opposing portion, the movable member moves toward the upstream side in the conveying direction of the recording material by the pressing force of the rotating body against the end face opposing portion.

According to a third aspect of the present invention, there is provided a fixing device comprising a tubular flexible rotating body rotating while contacting with a recording material on which an image is formed, and an outer surface opposed portion facing the outer surface of the rotating body at an end portion in the direction of the bus- And the outer surface facing portion moves toward the upstream in the recording material conveying direction in accordance with the lateral movement in the direction of the bus bar of the rotating body.

Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings.

1 is a sectional view of an image forming apparatus;
2 is a cross-sectional view of a fixing device;
3 (a) and 3 (b) are a perspective view and a cross-sectional view, respectively, of the interior of the fixing device.
4 (a) and 4 (b) are a perspective view and a cross-sectional view, respectively, of the correction mechanism according to the first embodiment;
5 (a) and 5 (b) are perspective views of the movable member and the holding member.
6 is a sectional view of a correction mechanism;
7 (a) and 7 (b) are diagrams for explaining the operation of the correction mechanism, respectively.
8 (a) and 8 (b) are views each showing a force applied to the belt.
9 is a view showing a force applied to the movable member;
10 (a) and 10 (b) are perspective views of the movable member and the holding member according to the second embodiment, respectively.
11 is a sectional view of a correction mechanism;
12 (a) and 12 (b) are diagrams for explaining the operation of the correction mechanism.
13 is a perspective view of a fixing device according to Embodiment 3. Fig.
14 (a) and 14 (b) are perspective views of the movable member and the holding member, respectively.
15 (a) and 15 (b) are a perspective view of the link member and a cross-sectional view of the correction mechanism;
16 (a) and 16 (b) are diagrams for explaining the operation of the correction mechanism.
17 (a) and 17 (b) are a perspective view and a top view, respectively, of the correction mechanism according to the fourth embodiment.
18 (a) and 18 (b) are diagrams for explaining the operation of the correction mechanism, respectively.
19 is a perspective view of a correction mechanism according to Embodiment 5. Fig.
20 (a) and 20 (b) are a perspective view and a cross-sectional view, respectively, of a correction mechanism according to a sixth embodiment;
21 (a) and 21 (b) are perspective views of the movable member and the holding member, respectively.
22 is a sectional view of a correction mechanism;
23 (a) and 23 (b) are diagrams for explaining the operation of the correction mechanism, respectively.
24 (a) to 24 (d) each show a force applied to the belt.
25 is a view showing a mechanism for regulating the posture of the movable member;
26 is a view showing a modification of the sixth embodiment;
Fig. 27 is a view showing Embodiment 7; Fig.
28 is a view showing a modification of the seventh embodiment;
29 is a view showing another modification of the seventh embodiment;
30 (a) and 30 (b) are a perspective view and a cross-sectional view, respectively, of the correction mechanism according to the eighth embodiment;
31A is a perspective view of the movable member, FIG. 31B is a perspective view of the holding member, and FIGS. 31C and 31D are views showing the holding member, respectively.
32 is a sectional view of a correction mechanism;
33 (a) and 33 (b) are diagrams for explaining the operation of the correction mechanism;
Figures 34 (a) and 34 (b) show the force applied to the belt, respectively.
35 is a view for explaining a mechanism for regulating the posture of the movable member;

First Embodiment

1 is a cross-sectional view of an electrophotographic printing type printer (image forming apparatus) 100 on which a fixing device 1 is mounted. The full color toner image formed by superimposing the four color toner images of the image forming portion 101 is transferred to the recording material P fed from the paper feeding unit by the transferring portion 102. [ The toner image transferred to the recording material P is heat-fixed to the recording material in the fixing device 1. [ The recording material P onto which the toner image is fixed is discharged to the discharge tray 103. In the case of double-sided printing, after the toner image is transferred and fixed on the first surface of the recording material, the recording material is reversed and conveyed to the double-sided conveying path 104 and an operation similar to that performed for image formation on the first surface An image is formed on the second surface of the recording material. Since this image forming operation is known, a detailed description will be omitted.

2 is a schematic cross-sectional view of the fixing device 1. Fig. 3 (a) is an internal perspective view of the fixing device. 3 (b) is a cross-sectional view of the inside of the fixing device when the fixing device is viewed from the recording material discharge side. The arrow S indicates the conveying direction of the recording material P, and the broken line X indicates the longitudinal center of the fixing device. In the fixing device of this embodiment, the dashed line X is a transporting reference of the recording material P. Regardless of the size of the recording material P, the recording material P is transported while aligning the center in the widthwise direction of the recording material with the broken line X.

The fixing device 1 has, for example, a heating unit 2, a roller 3 for forming a fixing nip portion together with the heating unit 2, and a conveying roller 4 for conveying the recording material to which the image is fixed. The heating unit 2 includes a tubular flexible rotating body 9 (hereinafter referred to as a belt 9) and a belt 9 in contact with the inner surface of the belt 9, And a heater (5) for heating the substrate. Further, the heating unit 2 includes, for example, a heater holder 6 and a stay 8. The heater holder (6) holds the heater (5). The stay 8 maintains the rigidity of the heating unit 5. In this embodiment, the heater 5, the heater holder 6, and the stay 8 constitute a backup unit which contacts the inner surface of the belt 9 in the direction of the bus bar. On the inner surface of the belt 9, no stretching roller is provided. Therefore, the belt 9 is not supported. The roller 3 has a rubber layer and forms a fixing nip portion N together with the backup unit via the belt 9. [ The fixing nip N carries the recording material sandwiched therebetween. The roller 3 is driven via the gear 61 by a motor (not shown). The belt 9 rotates in accordance with the rotation of the roller 3.

As shown in Fig. 3 (a), a U-shaped concave portion for mounting two bearings of the roller 3 is provided on the frame 13 of the fixing device. The two bearings provided at the respective axial ends of the roller 3 are held in the concave portion. Corresponding ends of the backup units are provided with correction mechanisms (also referred to as "moving mechanisms") 10L and 10R for correcting the inclination of the belt 9. By arranging the correction mechanism at this position, the correcting mechanisms 10L, 10R are opposed to the end face of the belt 9. The correction mechanisms 10L and 10R each have a holding member 12 (to be described later). 4 (a)) by providing the groove 12f of the holding member 12 in the U-shaped concave portion of the frame 13 so that the heating unit 2 is supported by the frame (not shown) 13). The compression spring 7 (first pressing member) applies pressure to the upper surface 12c of the holding member 12 (see Fig. 4 (a)). The heater 5 is urged toward the roller 3 through the holding member 12, the stay 8 and the heater holder 6 by the pressure applied by the spring 7. Thereby, the rubber layer of the roller 3 is compressed, and the backup unit and the roller 3 form the fixation nip portion N via the belt 9. The recording material P carrying the toner image is sandwiched and conveyed in the fixing nip N while being in contact with the belt 9. [ During this period, the toner image is heated by the heater 5 through the belt 9 and fixed to the recording material P. [

The belt 9 of the present embodiment includes a base layer (specifically, polyimide) made of a heat-resistant resin, a surface layer of a fluororesin, and a rubber layer (silicone rubber layer) formed between the base layer and the surface layer. The material of the base layer may be a metal such as stainless steel or nickel. The rubber layer may be omitted if not required.

The heater 5 may be formed long in the longitudinal direction of the fixing device (i.e., the direction of the bus bar 9) as shown in Fig. 3 (b). The heater 5 is a ceramic heater in which a heat generating resistor is printed on a ceramic substrate. Electric power is supplied to the heater 5 through the connector 62 for power supply. The temperature of the heater 5 is monitored by a temperature detecting element (not shown). The electric power supplied to the heater 5 is controlled so that the detected temperature of the temperature detecting element is maintained at the target temperature. The heater holder 6 is formed by molding a heat resistant resin such as LCP (liquid crystal polymer) or PPS (polyphenylene sulfide). The heater holder (6) has a groove for fitting the heater (5). And the heater 5 is held in the longitudinal direction by fitting the heater 5 into the groove. The stay 8 has a U-shaped cross section and is formed of a metal (iron in this embodiment). The stay 8 makes contact with the holder 6 in the longitudinal direction, and reinforces the holder 6.

Next, the correction mechanism 10R and the correction mechanism 10L for correcting the lateral movement of the belt 9 will be described with reference to Figs. 4 (a) to 8 (b). The shape of the correcting mechanism 10R and the shape of the correcting mechanism 10L are shapes that are substantially axially symmetrical with respect to the transporting reference X of the recording material P. [ Therefore, only the correction mechanism 10R will be described, and the description of the correction mechanism 10L will be omitted.

4 (a) is a perspective view of the correction mechanism 10R. 4 (b) is a cross-sectional view of the correction mechanism 10R when viewed from upstream in the conveying direction of the recording material. 5 (a) is a perspective view of the movable member 11 (to be described later). 5 (b) is a perspective view of the holding member 12 for holding the movable member 11. As shown in Fig. Fig. 6 shows the correction mechanism 10R when viewed from the direction of arrow VI in Fig. 4 (b). Figs. 7 (a) and 7 (b) and Figs. 8 (a) and 8 (b) are diagrams for explaining a mechanism for correcting the posture of the belt by the correction mechanism, respectively.

The correction mechanism 10R includes a movable member 11, a holding member 12 for holding the movable member 11, and a compression spring (second pressing member) 14 for pressing the movable member 11 . The holding member 12 is fitted to the U-shaped concave portion of the frame 13 of the fixing device, as described above. Thus, the position of the holding member 12 in the longitudinal direction of the heater and the position of the holding member 12 in the recording material carrying direction are roughly determined. Since the holding member 12 is urged toward the roller 3 by the spring 7, the holding member 12 is in a substantially fixed state.

The movable member 11 is a part movably coupled to the holding member 12. The movable member 11 is in contact with a notch provided at an end portion in the longitudinal direction of the stay 8. A slight gap is provided between the upper portion of the movable member 11 and the retaining member 12. [ As shown in Fig. 4 (a), the movable member 11 has an end face opposing portion 11a opposed to the end face of the belt 9. When the belt 9 is laterally moved in the direction of the busbars, the end face of the belt 9 collides with the end face opposing portion 11a. The movable member 11 has an inner surface opposed portion 11c which is opposed to the inner surface of the end portion of the belt 9. A slight gap is provided between the inner surface of the belt 9 and the inner surface facing portion 11c. The inner surface facing portion 11c has a function of guiding the inner surface of the belt 9 when the belt 9 rotates.

As shown in Fig. 5 (a), the movable member 11 has a convex portion 11b extending in the oblique direction with respect to the longitudinal direction of the heater. As shown in Fig. 5 (b), the holding member 12 has a concave portion (guide) 12b extending in an oblique direction with respect to the longitudinal direction of the heater. The convex portion 11b of the movable member 11 is fitted to the concave portion 12b of the holding member 12 when the movable member 11 and the holding member 12 are combined. With this configuration, the movable member 11 is slidably held along the concave portion 12b of the holding member 12. [ Reference numeral 14 denotes a compression spring for urging the movable member 11 in a direction away from the seat surface 12a of the retaining member 12. [

Next, the operation of the correction mechanism 10 will be described with reference to Figs. 6 to 8B. 6 and 7A show the state of the correction mechanism when the end surface of the belt 9 is not in contact with the end surface facing portion 11a. The belt 9 is located on the upstream side of the heater 5 in the rotational direction of the belt 5 when the belt 9 is driven to rotate by the rotation of the roller 3, (11c). On the other hand, the belt 9 is spaced from the inner surface facing portion 11c of the movable member 11 in the region on the downstream side of the rotational direction of the belt than the heater 5.

When the end surface of the belt 9 is not in contact with the end surface facing portion 11a, the movable member 11 pressed by the spring 14 is most distant from the seat surface 12a of the holding member 12 Position. At this time, even if the convex portion 11b of the movable member 11 collides with the first stopper portion 12d of the retaining member 12 and is pressed by the spring 14, the movement of the movable member 11 is restricted , The position of the movable member 11 is determined.

7 (a), when the end face of the belt 9 does not contact the end face opposing portion 11a, the end face of the belt 9 and the end face of the movable member 11 are opposed to each other The distance between the portions 11a is D1. The distance from the seat surface 12a of the holding member 12 to the end surface facing portion 11a of the movable member 11 is D2.

7B shows that the belt 9 is laterally moved in the direction of the arrow M1 so that the end face of the belt 9 contacts the end face opposing portion 11a and the belt 9 9 press the movable member 11 in the direction of the arrow M1.

For example, when the belt 9 is laterally moved toward the movable member 11 as a result of, for example, the rollers 3 and the belt 9 being out of alignment with each other, And contacts the member (11). When the belt 9 further moves laterally, the belt 9 pushes the movable member against the urging force of the spring 14 in the direction of the arrow M1, and the movable member 11 moves. The convex portion 11b of the movable member 11 moves along the concave portion 12b of the holding member 12 and the movable member 11 moves in the direction of the arrow M2. The movable member 11 stops moving when the convex portion 11b collides with the second stopper portion 12g of the concave portion 12b. 7 (b), the distance from the seat surface 12a of the retaining member 12 to the end surface facing portion 11a of the movable member 11 is D3 (< D2). The movable member 11 is moved to the distance D4 toward the upstream side of the recording material conveying direction S, as compared with the state of Fig. 7 (a).

As described above, when the belt 9 is rotating, the inner surface of the belt 9 is brought into contact with the inner surface facing portion 11c of the movable member 11. 7 (b), when the movable member 11 moves toward the upstream side in the recording material conveying direction S, the inner surface facing portion 11c presses the inner surface of the belt 9, The belt end on the side of the recording medium 10R moves toward the upstream side of the recording material conveying direction S. Conversely, the correcting mechanism 10L positioned opposite to the correcting mechanism 10R in the longitudinal direction of the heater is not pressed by the end face of the belt 9, so that the movable member of the correcting mechanism 10L does not move.

When the moving direction of the belt 9 is the opposite direction, that is, when the belt collides with the correcting mechanism 10L, only the movable member in the correcting mechanism 10L moves the upstream side of the recording material conveying direction S Lt; / RTI &gt; By this movement, the belt end portion on the side of the correction mechanism 10L moves toward the upstream side of the recording material conveying direction S.

In this way, when the belt 9 is laterally moved in the heater longitudinal direction (i.e., the direction of the busbars of the belt) and collides with one of the correcting mechanisms 10R and 10L, the belt 9 ) Is urged toward the upstream side in the recording material conveying direction. By this principle, the alignment state of the belt 9 with respect to the roller 3 is changed and the orientation of the belt is corrected so that the belt is moved away from the movable member (that is, Direction), the force applied to the end face of the belt 9 is suppressed. This can suppress the breakage of the belt. As described above, the movable member 11 is urged by the spring 14. Therefore, when the belt 9 is moved in the direction opposite to the direction of the arrow M1 from the state shown in Fig. 7 (b), the movable member 11 is moved to the position shown in Fig. 7 (a) And the position shown in (b).

Next, the principle of reducing the stress applied to the end face of the belt 9 will be further described with reference to Figs. 8 (a) and 8 (b). 8 (a) and 8 (b) show the heating unit 2 and the roller 3 viewed from the side of the belt 9, respectively. 8 (a) shows a state in which the belt is moved in the lateral direction. Figure 8 (b) shows a state in which the belt is no longer moved laterally.

Generally, the lateral movement of the belt 9 in the direction of the busbar is caused by the misalignment of the roller 3 and the belt 9 with respect to each other. 8 (a) shows a state in which the roller 3 and the belt 9 are misaligned with respect to each other. 8A shows that the belt end of the correction mechanism 10R side is inclined toward the downstream side of the recording material conveyance direction S and the belt end of the correction mechanism 10L side is located on the upstream side of the recording material conveyance direction S Indicating an augmented state. The force F is applied to the belt 9 by the rotation of the roller 3, as shown in Fig. 8 (a). The force F can be decomposed into the force Fl in the direction of the busbars of the belt 9 and the force F2 in the direction orthogonal to the direction of the busbars. The belt 9 is moved laterally toward the correction mechanism 10R by the force F1. The movable member 11 is guided to the holding member 12 and moves toward the upstream side of the recording material conveying direction S. When the belt 9 touches and presses the movable member 11 of the correcting mechanism 10R, The movement of the movable member 11 corrects the orientation of the belt 9 as shown in Fig. 8 (b) based on the above-described principle. The angle between the force F and the direction of the busbars of the belt 9 changes because there is no further misalignment between the roller 3 and the belt 9. [ As a result, the force F1 is reduced, and the stress applied to the end face of the belt 9 is also reduced.

The magnitude of the force Fl varies depending on the amount of movement of the movable member 11. 9 shows the relationship between the pressing force of the movable member 11 by the belt 9 and the pressing force of the movable member 11 by the spring 14 in accordance with the movement amount of the movable member 11 in the heater longitudinal direction . As shown in Fig. 9, when the belt 9 starts to press the movable member 11, one of the end portions of the belt is pressed by the inner surface facing portion 11c of the movable member and is gradually aligned. That is, as the amount of movement of the movable member increases, the amount of movement of the movable member toward the upstream side in the recording material conveying direction increases, so that the correction amount of the orientation (inclination) of the belt increases and the force F1 decreases. As the amount of movement of the movable member increases, the pressing force of the movable member 11 by the spring 14 gradually increases. When the force when the belt 9 starts to press the movable member 11 is small, that is, when the force F1 is small, the movable member 11 is rotated by the force F1 and the spring 14 ) Is in a balanced state (state 1). If the force when the belt 9 starts to push the movable member 11 is great, that is, if the force F1 is large, the maximum movement amount D2 - D3 is set before the force of the force F1 and the force of the spring 14 is balanced And the movable member 11 stops at the position where the maximum movement amount has been reached (state 2). A gap is provided between the inner surface of the belt and the inner surface facing portion 11c so that the contact state between the inner surface facing portion 11c and the inner surface of the belt is maintained even when the movable member 11 is moved by the maximum movement amount D2- do. Between the inner surface of the belt and the inner surface facing portion 11c so that the contact state between the inner surface facing portion 11c and the inner surface of the belt is maintained even when the movable member 11 moves to the distance D4 upstream in the recording material conveying direction A gap is provided.

The stress applied to the end face of the belt 9 can be reduced as described above, so that the wear of the end face of the belt 9 can be suppressed.

In this embodiment, the correction mechanism is provided at both opposite ends of the belt, but the above-described correction mechanism can be provided only to the side where the belt is laterally shifted and the belt is laterally shifted in a predetermined direction in one direction. In this embodiment, it is assumed that the length of the belt is shorter than the width between the two movable members. However, the length of the belt can be approximately the same as the width between the two movable members, that is, the two ends of the belt can always be in contact with the two movable members. Further, although the inner and outer facing portions and the end surface facing portions are formed as one component serving as the movable member, the inner surface facing portion and the end surface facing portion may be separate parts. This applies to another embodiment described later.

Second Embodiment

Next, the fixing apparatus according to the second embodiment will be described focusing on the difference from the first embodiment. 10 (a) is a perspective view of the movable member 21. Fig. 10 (b) is a perspective view of the holding member 22 holding the movable member 21. As shown in Fig. 11 shows one of the two correction mechanisms and shows the correction mechanism 20R when viewed in the same direction as the direction of arrow VI in Fig. 4 (b). 12A and 12B show mechanisms for correcting the orientation of the belt 9 by the correction mechanism 20R, respectively.

The correction mechanism 20R includes a movable member 21, a holding member 22 holding the movable member 21, a tension spring 24 for pressing the movable member 21, and a link member 25.

The movable member 21 includes an end face opposing portion 21a, a convex portion 21b, and an inner face opposing portion 21c. The end face opposing portion 21a collides with the end face of the belt when the belt 9 is moved in the lateral direction. The inner surface facing portion 21c faces the inner surface of the end portion of the belt in the direction of the busbars. The movable member 21 includes the convex portion 21d and the support portion 21e of the tension spring 24. [ The convex portion 21d rotatably holds the link member 25 (to be described later).

The holding member 22 holding the movable member 21 has a surface 22a and a concave portion 22b. The face 22a is substantially parallel to the end face opposing portion 21a of the movable member 21. [ The concave portion 22b guides the convex portion 21b of the movable member 21. The holding member 22 also has the convex portion 22d, the support portion 22e of the tension spring 24, and the groove portion 22f. The convex portion 22d serves as a rotation center of the link member 25. [ The groove portion 22f is provided to engage the holding member 22 in the U-shaped concave portion of the apparatus frame 13. The link member 25 is provided so as to connect the convex portion 21d and the convex portion 22d.

Next, the operation of the correction mechanism 20R will be described. 12 (a), when the end face of the belt 9 does not contact the end face opposing portion 21a, the end face of the belt 9 and the end face of the movable member 21 are opposed to each other, Lt; RTI ID = 0.0 &gt; D1. &Lt; / RTI &gt; The distance from the surface 22a of the holding member 22 to the end surface facing portion 21a of the movable member 21 is D2.

12B shows a state in which the end face of the belt 9 comes into contact with the end face opposing portion 21a as a result of the lateral movement of the belt 9 in the direction of the arrow M1 and the resistance against the pressing force of the spring 24 And the belt 9 presses the movable member 21 in the direction of arrow M1. When the belt 9 presses the movable member 21, the convex portion 21b is guided by the concave portion 22b and moves in the direction of the arrow M3. During this movement, the link member 25 rotates about the convex portion 22d. By the action of the link member 25, the movable member 21 moves in parallel to the direction of the arrow M3 without changing its orientation from the state shown in Fig. 12 (a). When the convex portion 21b is moved to the end of the concave portion 22b, the movable member 21 stops moving. 12 (b), the distance from the surface 22a of the holding member 22 to the end surface facing portion 21a of the movable member 21 is D3 (< D2). The movable member 21 moves to the distance D4 toward the upstream side of the recording material conveying direction S, as compared with the state shown in Fig. 12 (a).

When the movable member 21 moves toward the upstream side in the recording material conveying direction S, the inner surface opposed portion 21c presses the inner surface of the belt 9, and as a result, the belt end of the correction mechanism 20R side And moves toward the upstream side of the direction S. Conversely, since the correction mechanism 20L (not shown) positioned opposite to the correction mechanism 20R in the heater longitudinal direction is not pressed by the end face of the belt 9, the movable member of the correction mechanism 20L does not move Do not.

As described above, when the movable member moves, the alignment of the belt 9 with respect to the roller 3 changes based on the same principle as that used in the first embodiment, and the orientation of the belt is corrected. Thereby, the force applied to the end face of the belt 9 is suppressed as the belt moves away from the movable member (i.e., in the direction opposite to the direction of the arrow M1 shown in Fig. 12 (b)). This can suppress the breakage of the belt.

Third Embodiment

Next, the fixing device according to the third embodiment will be described focusing on the differences from the first and second embodiments. 13 is a perspective view of a fixing device. Fig. 14 (a) is a perspective view of the movable member 31. Fig. Fig. 14 (b) is a perspective view of the holding member 32 holding the movable member 31. Fig. 15 (a) is a perspective view of an end portion of the link member 36 (to be described later). Fig. 15B shows one of the two correction mechanisms and shows the correction mechanism 30R viewed from the same direction as the direction of the arrow VI shown in Fig. 4B. 16A and 16B show mechanisms for correcting the orientation of the belt 9 by the correction mechanisms 30R and 30L, respectively.

The correction mechanisms 30R and 30L include a movable member 31 and a holding member 32 holding the movable member 31, respectively. The link members 36 connecting the two movable members 31 are provided in the correction mechanisms 30R and 30L.

Each of the movable members 31 includes an end face opposing portion 31a, a convex portion 31b, and an inner face opposing portion 31c. Each end face opposing portion 31a collides with the end face of the belt when the belt 9 is moved in the lateral direction. Each of the inner surface facing portions 31c faces the inner surface of the belt in the direction of the busbars. Each of the movable members 31 has a hole 31d for rotatably holding the link member 36 (to be described later).

Each holding member 32 holding the corresponding movable member 31 has a surface 32a and a concave portion 32b. Each of the surfaces 32a is substantially parallel to the end surface opposed portion 31a of the corresponding movable member 31. [ Each of the concave portions 32b guides the convex portion 31b of the corresponding movable member 31. [ Each holding member 32 further has a groove portion 32f for fitting the holding member 32 corresponding to the U-shaped concave portion of the apparatus frame 13.

The apparatus according to the third embodiment includes a link member 36 connecting the movable member of the correction mechanism 30R and the movable member of the correction mechanism 30L. The link member 36 includes a shaft 36R inserted into the hole 31d of the movable member of the correcting mechanism 30R and a shaft 36L inserted into the hole 31d of the movable member of the correcting mechanism 30L. .

Next, the operation of the correction mechanism 30R and the correction mechanism 30L will be described. 16 (a), when the end face of the belt 9 does not contact the end face opposing portion 31a, the end faces of the belt 9 and the end face of the movable member 31 The distance between the opposing portions 31a is D1. The distance from the surface 32a of each holding member 32 to the end surface facing portion 31a of the corresponding movable member 31 is D2.

16B shows that the end face of the belt 9 comes into contact with the end face opposing portion 31a of the movable member of the correcting mechanism 30R as a result of the lateral movement of the belt 9 in the direction of arrow M1 , And the belt 9 presses the movable member 31 in the direction of arrow M1. When the belt 9 presses the movable member 31, the movable member of the correcting mechanism 30R moves in the direction of arrow M4 while the convex portion 31b is guided by the concave portion 32b. The movable member of the correcting mechanism 30L and the movable member of the correcting mechanism 30R are connected by the link member 36. [ The two movable members move in mutual movement. Therefore, when the movable member of the correcting mechanism 30R moves in the direction of arrow M4, the movable member of the correcting mechanism 30L moves in the direction of arrow M5. That is, when the movable member of the correcting mechanism 30R moves upstream in the recording material counter-current direction, the movable member of the correcting mechanism 30L moves downstream in the recording material conveying direction.

16B, the distance D3 is a distance from the surface 32a to the end face confronting portion 31a when the convex portion 31b is moved to the end portion of the concave portion 32b. At this time, the moving distance of the two movable members in the recording material conveying direction is all D4. When the belt 9 is laterally moved toward the correcting mechanism 30L, the moving direction of the two movable members in the recording material conveying direction is opposite to the direction shown in Fig. 16B.

With the above-described configuration, the inclination of the belt 9 in the direction of correction of the lateral movement of the belt is increased, so that the performance of correcting the lateral movement of the belt is enhanced, compared with a configuration in which only one of the movable members is moved.

Fourth Embodiment

Next, the fixing device according to the fourth embodiment will be described focusing on the differences from the first to third embodiments.

The correction mechanism according to the fourth embodiment includes a sensor 46 for detecting the lateral movement of the belt 9 and is configured to move the movable member by the power of the motor And is moved upstream in the transport direction.

17A is a perspective view of the correcting mechanism 40L. Fig. 17B shows the correction mechanism 40L viewed from the correction mechanism 40L. The correction mechanism 40R disposed on the opposite side also has the same configuration. 18 (a) and 18 (b) show the operation of the correction mechanism.

A photosensor (46) is disposed above the movable member (41). The sensor 46 detects the movement of the movable member 41 in the direction of the belt bus line. When the belt 9 is not in contact with the movable member 41 and the movable member is not moving, the movable member 41 is at the position shown in Fig. 18 (a) Is not reflected by the sensor. However, when the movable member 41 moves in the direction of the belt bus line by the lateral movement of the belt 9, the movable member 41 moves to the position shown in Figure 18 (b), and the reflected light from the light source And is detected by the sensor 46. According to this output, the motor (not shown) rotates the gear 40RG engaged with the gear 41hG provided in the rack 41h of the movable member 41 to rotate the movable member 41 in the direction of arrow M6, That is, upstream of the recording material conveying direction.

Thereby, the alignment of the belt 9 with respect to the roller 3 is changed based on the same principle as that used in the first embodiment, and the posture of the belt is corrected. Thereby, the belt is moved in the direction away from the movable member, and the force applied to the end face of the belt 9 is suppressed.

In the fourth embodiment, the movable member can be moved in the direction of the arrow M6 before the end face of the belt contacts the end face opposing portion of the movable member.

Fifth Embodiment

Next, the fixing device according to the fifth embodiment will be described focusing on differences from the first to fourth embodiments.

The movable member according to the fifth embodiment is different from the other embodiment in that the portion pressing the belt toward the upstream side in the recording material conveying direction is opposed to the outer surface of the belt to correct the posture of the belt. 19 is a perspective view of a correction mechanism 50R of the device according to the fifth embodiment. The correction mechanism 50R includes a movable member 51 and a holding member 52. [ The movable member 51 includes an outer surface opposed portion 51j opposed to the outer surface of the end portion of the belt. When the belt is moved in the lateral direction to press the movable member, the outer surface opposed portion 51j of the movable member presses the end portion of the belt toward the upstream side in the recording material conveying direction by using the force caused by the pressing. Thereby, the alignment of the belt 9 with respect to the roller 3 is changed based on the same principle as that used in the first embodiment, and the posture of the belt is corrected. Thereby, the belt is moved in the direction away from the movable member, and the force applied to the end face of the belt 9 is suppressed.

Sixth Embodiment

Next, correction mechanisms 110R and 110L for correcting the inclination of the belt 9 according to the sixth embodiment will be described with reference to Figs. 20A to 24D. The shape of the correcting mechanism 110R and the shape of the correcting mechanism 110L are substantially axially symmetrical with respect to the conveying reference X of the recording material P. [ Therefore, mainly the correction mechanism 110R will be described and the correction mechanisms 110R and 110L will be explained by partially explaining the correction mechanism 110L.

20A is a perspective view of the correction mechanism 110L. 20B is a sectional view of the correction mechanism 110R when viewed from the upstream side in the recording material conveyance direction. 21 (a) is a perspective view of the movable member 111 (to be described later). Fig. 21 (b) is a perspective view of the holding member 112 for holding the movable member 111. Fig. Fig. 22 is a view showing the correction mechanism 110R when viewed from the direction of arrow XXII in Fig. 20 (b). Figs. 23A and 23B and Figs. 24A to 24D are views showing a mechanism for correcting the posture of the belt by the correction mechanism, respectively.

The correction mechanism 110R includes a movable member 111, a holding member 112 for holding the movable member 111, and a compression spring (pressing member) 14 for pressing the movable member 111 . As described above, the holding member 112 is fitted to the U-shaped concave portion of the frame 13 of the fixing device. Thus, the position of the holding member 112 in the longitudinal direction of the heater and the position of the holding member 112 in the recording material conveying direction are roughly determined. Since the holding member 112 is urged toward the roller 3 by the spring 7, the holding member 112 is in a substantially fixed state.

The movable member 111 is a part movably coupled to the holding member 112. The movable member 111 is in contact with a cutout provided at an end portion of the stay 8 in its longitudinal direction. A slight gap is provided between the upper portion of the movable member 111 and the holding member 112. [ As shown in Fig. 20 (a), the movable member 111 has an end face opposing portion 111a opposed to the end face of the belt 9. When the belt 9 is laterally moved in the direction of the busbars, the end face of the belt 9 collides with the end face opposing portion 111a. The movable member 111 has an inner surface facing portion 111c which is opposed to the inner surface of the end portion of the belt 9. A slight clearance is provided between the inner surface of the belt 9 and the inner surface facing portion 111c. The inner surface facing portion 111c has a function of guiding the inner surface of the belt 9 when the belt rotates.

As shown in Fig. 21 (a), the movable member 111 has a convex portion 111b extending obliquely with respect to the longitudinal direction of the heater. As shown in Fig. 21 (b), the holding member 112 has a concave portion (guide) 112b that extends obliquely with respect to the longitudinal direction of the heater. The convex portion 111b of the movable member 111 is fitted into the concave portion 112b of the holding member 112 when the movable member 111 and the holding member 112 are combined. With this configuration, the movable member 111 is slidably held along the concave portion 112b of the holding member 112. [ Reference numeral 14 denotes a compression spring for urging the movable member 111 in a direction away from the seat surface 112a of the retaining member 112. [

Next, the operation of the correction mechanism 110 will be described with reference to Figs. 22 to 24 (d). 22 and 23 (a) show the state of the correction mechanism in which the end face of the belt 9 is not in contact with the end face opposing portion 111a. When the belt 9 is driven to rotate by the rotation of the roller 3, the belt 9 rotates in the direction of rotation of the belt in the region disposed upstream of the heater 5, And comes into contact with the opposing portion 111c. On the other hand, the belt 9 is spaced from the inner surface facing portion 111c of the movable member 111 in the region disposed downstream of the heater 5 in the rotational direction of the belt.

When the end face of the belt 9 is not in contact with the end face opposing portion 111a, the movable member 111 pressed by the spring 14 moves away from the seat surface 112a in the retaining member 112 Position. At this time, even if the convex portion 111b of the movable member 111 hits the first stopper 112d of the retaining member 112 and is pressed by the spring 14, the movable member 111 moves to the side of the movable member 111, So that the movement of the movable member is restricted.

23 (a), when the end face of the belt 9 does not contact the end face opposing portion 111a, the end face of the belt 9 and the end face of the movable member 111 The distance between the opposing portions 111a is D1. The distance from the seat surface 112a of the holding member 112 to the end surface facing portion 111a of the movable member 111 is D2.

23B shows a state in which the end face of the belt 9 comes into contact with the end face opposing portion 111a as a result of the lateral movement of the belt 9 in the direction of the arrow M1, And the belt 9 presses the movable member 111 in the direction of arrow M1.

For example, when the belt 9 is laterally moved toward the movable member 111 as a result of the rollers 3 and the belt 9 not being aligned with each other, And contacts the member 111. When the belt 9 is further moved in the lateral direction, the belt 9 pushes the movable member against the urging force of the spring 14 in the direction of the arrow M1 so that the movable member 111 moves the force of the lateral movement of the belt . The convex portion 111b of the movable member 111 moves along the concave portion 12b of the holding member 112 so that the movable member 111 moves in the direction of the arrow M2. When the convex portion 111b hits the second stopper 112g of the concave portion 112b, the movable member 111 stops moving. 23 (b), the distance from the seat surface 112a of the holding member 112 to the end surface facing portion 111a of the movable member 111 is D3 (< D2). 23A, the movable member 111 is moved toward the upstream side of the recording material conveying direction S by the distance D4.

As described above, when the belt 9 is rotating, the inner surface of the belt 9 is in contact with the inner surface opposed portion 111c of the movable member 111. 23 (b), the movable member 111 is moved toward the upstream side in the recording material conveying direction S, and the inner surface facing portion 111c pushes the inner surface of the belt 9, The end of the belt on the mechanism 110R side moves toward the upstream side of the recording material conveying direction S. On the other hand, since the correction mechanism 110L positioned opposite to the correction mechanism 110R in the longitudinal direction of the heater is not pressed by the end face of the belt 9, the movable member of the correction mechanism 110L does not move .

Only the movable member in the correcting mechanism 110L is moved toward the upstream side of the recording material conveying direction S when the moving direction of the belt 9 is the opposite direction, Move. By this movement, the end of the belt on the side of the correcting mechanism 110L is moved toward the upstream side of the recording material conveying direction S.

In this way, when the belt 9 is laterally moved in the longitudinal direction of the heater (that is, the direction of the busbars of the belt) and strikes one of the correcting mechanisms 110R and 110L, 9 are urged toward the upstream side in the recording material conveying direction. With this principle, the alignment of the belt 9 with respect to the roller 3 is changed, the posture of the belt is corrected, and the direction in which the belt 9 is separated from the movable member (that is, the direction of the arrow M1 shown in FIG. The force applied to the end face of the belt 9 is suppressed. Thus, breakage of the belt can be suppressed. As described above, the movable member 111 is urged by the spring 14. 23 (b), when the belt 9 is moved in the direction opposite to the direction of the arrow M1, the movable member 111 moves from the position shown in Fig. 23 (a) (a) and (b).

Next, the principle of reducing the stress applied to the end surface of the belt 9 will be further described with reference to Figs. 24A to 24C. 24 (a) to 24 (c) show the heating unit 2 and the roller 3 as viewed from the side of the belt 9, respectively. 24 (a) shows a state in which the belt is moved in the lateral direction. Figure 24 (b) shows a state in which the belt is no longer moved in the lateral direction. 24 (c) shows a state in which the warp of the belt 9 is corrected.

Generally, the lateral movement of the belt 9 in the direction of the busbars is due to the fact that the rollers 3 and the belt 9 are not aligned with each other. 24 (a) shows a state in which the roller 3 and the belt 9 are not aligned with each other. 24A shows that the end of the belt on the side of the correcting mechanism 110L is inclined toward the downstream side of the recording material conveying direction S and the end of the belt on the side of the correcting mechanism 110R is positioned on the upstream side of the recording material conveying direction S Lt; / RTI &gt; The force F is applied to the belt 9 by the rotation of the roller 3, as shown in Fig. 24 (a). The force F can be decomposed into the force F1 in the direction of the busbars of the belt 9 and the force F2 in the direction perpendicular to the direction of the busbars. The belt 9 is moved laterally toward the correcting mechanism 110L by the force F1. The belt 9 is brought into contact with the movable member 111 of the correcting mechanism 110L so that the movable member 111 is guided by the holding member 112 so as to move in the direction And moves toward the upstream side. The movement of the movable member 111 corrects the posture of the belt 9 as shown in Fig. 24 (c) based on the above-described principle. The angle between the force F and the direction of the busbars of the belt 9 is changed because the alignment deviation between the roller 3 and the belt 9 is eliminated. As a result, the force F1 is reduced (F1 becomes F1 ') and the stress applied to the end face of the belt 9 is also reduced.

As described above, since the stress applied to the end face of the belt 9 can be reduced, the wear of the end face of the belt 9 can be suppressed.

The conveying force applied to the belt 9 as a result of the rotation of the pressure roller 3 is equal to or higher than the conveying force applied to the belt 9 when the position of the center of the roller portion of the pressure roller 3 is shifted from the position of the center of the sheet S in the width direction The belt 9 becomes uneven at both ends thereof. For example, as shown in Fig. 24D, when the sheet S is shifted toward the correction mechanism 110R side, the pressure roller 3 Is in contact with the belt 9 is longer. The frictional force between the pressure roller 3 and the belt 9 is greater than the frictional force between the paper and the belt 9. [ Therefore, the rotational force of the belt 9 generated by the pressure roller 3 is larger than the rotational force Fr in the correcting mechanism 110R, and the rotational force Ff in the correcting mechanism 110L is larger. As a result, the rotation of the end of the belt at the side of the correction mechanism 110R is delayed. Therefore, the end of the belt at the side of the correcting mechanism 110R is moved by the force T toward the upstream side in the sheet conveying direction. At this time, the end of the belt at the side of the correction mechanism 110R presses the movable member 111 toward the upstream side in the sheet conveying direction. The pressed movable member 111 tends to rotate in the direction of arrow W about the contact point P between the concave portion 112b and the convex portion 111b and starts to be inclined as shown in Fig. The movable member 111 is inclined so that the hatching portion Y of the movable member 111 is displaced toward the upstream side in the sheet conveying direction when the force T exceeds the force Tlimit that causes the movable member 111 to be displaced in position, It is misaligned. The alignment of the belt 9 with respect to the rotation axis (one-dot chain line) of the pressure roller is shifted as shown in Fig. 24 (a). Therefore, in order to prevent the movable member 111 from tilting, a tilt restricting mechanism for restricting the inclination of the movable member (inner surface facing portion) is provided. More specifically, the first engaging portion 111h is provided on the end face facing portion 111a of the movable member 111, and the second engaging portion 112h is provided on the holding member 112. [ That is, the inclination regulating mechanism includes a first engaging portion provided on the end face opposing portion and a second engaging portion provided on the retaining member and engaged with the first engaging portion.

When the movable member 111 begins to be inclined, the first engaging portion 111h and the second engaging portion 112h come into contact with each other. As a result, the movable member 111 is prevented from further inclining. In a state where the inclination of the movable member is restricted as a result of the first engaging portion 111h and the second engaging portion 112h being in contact with each other, at the point P, which is the rotational center of the movable member in the direction of arrow W, The convex portion 111b and the concave portion (guide) 112b of the holding member come into contact with each other. However, in the direction of the arrow W, the convex portion and the concave portion are separated from each other at the other portion (that is, the portion near the point Q in Fig. 25). According to the experiment, the inclination regulating mechanism makes it possible to increase the force TLimit, which causes the movable member to be displaced by 1.8 times when the portion Y of the movable member is pressed toward the upstream side in the carrying direction. In the sixth embodiment, the contact surfaces of the two engaging portions are formed so as to be parallel to the sheet conveying direction, but the contact surfaces may be shaped to be inclined with respect to the conveying direction. Thereby, it is possible to continue the alignment of the belt 9 without inclining the movable member 111, and it is possible to continuously regulate the lateral movement of the belt while reducing the stress applied to the end face of the belt.

In the present embodiment, the rotational force F transmitted from the pressure roller 3 to the belt 9 becomes non-uniform in the longitudinal direction as a result of conveying the sheet S shifted from the normal position in the width direction, When a force T for moving the end surface of the sheet conveying device toward the upstream side in the sheet conveying direction is generated.

The first latching portion and the second latching portion may have the shape shown in Fig. In Fig. 26, the holding member 212 of the correcting mechanism 210R is provided with a rib-shaped portion (second latching portion) 212h, a protruding portion (first latching portion) 211h is provided on the movable member 211, The protrusion 211h is held by the rib-shaped portion 212h. Even in this configuration, it is possible to reliably prevent the movable member from being displaced toward the upstream side in the sheet conveying direction by the pressing force from the belt, on the side where the belt is not moved in the lateral direction. 26, reference numerals 211b, 212b, and 212d denote parts having the same functions as those of the protruding portion 111b, the recessed portion 112b, and the stopping portion 112d shown in Fig. 22, .

Seventh Embodiment

Next, a seventh embodiment of the present invention will be described with reference to Figs. 27 to 29. Fig. The description of the same portions as those of the sixth embodiment is omitted. In Embodiment 6, the holding member regulates the inclination of the movable member, but in the seventh embodiment, the components other than the holding member regulate the inclination of the movable member.

In the example shown in Fig. 27, the movable member 311 is provided with a protruding portion (first engaging portion) 311h, and the pressing stay 308 is provided with a groove portion (second engaging portion) 311h to which the protruding portion 311h is fastened. 308h. 27, when the belt 9 is laterally moved toward the correcting mechanism 310L on the opposite side of the correcting mechanism 310R, the movable member 311 in the correcting mechanism 310R is pressed by the urging member 14 And collides with the pressurized stay 308, whereby the protruding portion 311h and the groove portion 308h are engaged with each other.

The movable member 311 in the correcting mechanism 310R is urged toward the upstream side in the sheet conveying direction when the force T for causing the belt 9 and the pressurizing roller 3 to shift in alignment is applied as in the sixth embodiment. The pressed movable member 311 is inclined in the W direction about the contact point P between the slide rib-shaped portion 311b and the guide portion 312b. At this time, since the projecting portion 311h of the movable member 311 and the groove portion 308h of the press stay 308 are fastened to each other, the movable member 311 is prevented from being inclined.

In the example shown in Fig. 28, a protruding portion (second engaging portion) 408h is provided on the side of the press stay 408 on the downstream side in the sheet conveying direction, and the protruding portion 408h is provided on the side of the press stay 408, (First engaging portion) 411h, thereby preventing the movable member 411 from tilting.

29, protruding portions (second engaging portions) 506h are provided on the side of the heater holder 506 (which holds the ceramic heater 505) on the downstream side in the sheet conveying direction, and the protruding portions 506h (First engaging portion) 511h of the movable member 511 to prevent the movable member 511 from tilting. In FIGS. 27 to 29, the reference numerals 311b, 312b, 411b, 412b, 511b, and 512b are components having the same functions as those of the convex portion 111b and the concave portion 112b shown in FIG. The description will be omitted.

Eighth Embodiment

Next, correction mechanisms 610R and 610L for correcting the inclination of the belt 9 of the eighth embodiment will be described with reference to Figs. 30 to 34. Fig. The shape of the correcting mechanism 610R and the shape of the correcting mechanism 610L are shapes that are substantially line symmetrical with reference to the conveying reference X of the recording material P. [ Therefore, mainly the correction mechanism 610R will be described and the correction mechanisms 610R and 610L will be described by partially explaining the correction mechanism 610L.

30 (a) is a perspective view of the correcting mechanism 610L. 30B is a cross-sectional view of the correction mechanism 610L when viewed from the downstream side in the transport direction of the recording material. 31A is a perspective view of the movable member 611 (to be described later). 31 (b) to 31 (d) are a perspective view, a front view, and a cross-sectional view taken along the line XXXID of the holding member 612 holding the movable member 611. Fig. 32 is a view of the correction mechanism 610L when viewed from the direction of the arrow XXXII in Fig. 30 (b). Each of Figures 33 (a) to 34 (b) shows a mechanism for correcting the orientation of the belt by the correcting mechanism.

The correction mechanism 610L includes a movable member (regulating member) 611, a holding member 612 holding the movable member 611, and a compression spring (pressing member) 614 (614a, 614b )). As described above, the holding member 612 is fitted in the U-shaped concave portion of the frame 13 of the fixing apparatus. Thus, the position of the holding member 612 in the longitudinal direction of the heater and the position of the holding member 612 in the recording material conveying direction are roughly determined. Since the holding member 612 is pressed toward the roller 3 by the spring 7, the holding member 612 is in a substantially fixed state.

The movable member 611 is a part that is movably fastened to the holding member 612. [ The movable member 611 is in contact with a notch provided at an end portion in the longitudinal direction of the stay 8. A slight clearance is provided between the upper portion of the movable member 611 and the retaining member 612. As shown in Fig. 30 (a), the movable member 611 has an end face confronting portion 611a which is opposed to the end face of the belt 9. When the belt 9 is laterally moved in the direction of the busbars, the end surface of the belt 9 collides with the end surface facing portion 611a. The movable member 611 has an inner surface opposed portion 611c which is opposed to the inner surface of the end portion of the belt 9. A slight clearance is provided between the inner surface of the belt 9 and the inner surface facing portion 611c. The inner surface facing portion 611c has a function of guiding the inner surface of the belt 9 when the belt is rotated.

As shown in Fig. 31 (a), the movable member 611 has a convex portion 611b extending in the oblique direction with respect to the longitudinal direction of the heater. 31 (b) to 31 (d), the holding member 612 has a recess (guide portion) 612b extending in the oblique direction with respect to the longitudinal direction of the heater. The convex portion 611b of the movable member 611 is fitted in the concave portion 612b of the holding member 612 when the movable member 611 and the holding member 612 are engaged. With this structure, the movable member 611 is slidably held along the concave portion 612b of the holding member 612. [

Reference numerals 614a and 614b denote compressing (compressing) the movable member 611 in a direction away from the seat surface 612a of the holding member 612 (i.e., pressing the movable member 611 toward the end surface of the belt) Refers to a spring (pressing member). In the present embodiment, a plurality of pressing members are provided. A coil spring is used as a pressing member. The coil springs 614a and 614b are moved in the region outside the region CA (see Fig. 32) in contact with the belt end face of the movable member 611 in a state in which the movable member 611 is not pressed by the belt 9 . As will be described later, the coil spring is arranged such that at least the position 614X at the center of the coil spring is located outside the area CA. The holding member 612 is provided with a spring holding sheet 612a on which a coil spring is mounted.

Next, the operation of the correction mechanism 610 will be described with reference to Figs. 32 to 34 (b). Each of Figs. 32 and 33 (a) shows the state of the correction mechanism when the end face of the belt 9 is not in contact with the end face opposing portion 611a. When the belt 9 is driven to rotate by the rotation of the roller 3, the belt 9 is moved in the region on the upstream side of the heater 5 in the rotational direction of the belt, (Not shown). On the other hand, the belt 9 is spaced from the inner surface facing portion 611c of the movable member 611 in the region on the downstream side of the heater 5 in the rotational direction of the belt.

When the end surface of the belt 9 is not in contact with the end surface opposing portion 611a, the movable member 611 pressed by the springs 614a and 614b is moved from the spring holding sheet 612a in the holding member 612 It is located at the farthest position. At this time, the movable member 611 collides with the stopper (not shown) provided on the holding member 612, so that even if the movable member 611 is pressed by the springs 614a and 614b, the movable member 611 Is restricted, and as a result, the shifting member 611 is positioned.

33 (a), when the end surface of the belt 9 is not in contact with the end surface opposing portion 611a, the end surface of the belt 9 and the end surface of the movable member 611 are opposed to each other The distance between the portions 611a is D1. The distance from the holding sheet 612a of the holding member 612 to the end surface confronting portion 611a of the movable member 611 is D2.

33B shows a state in which the end face of the belt 9 is in contact with the end face opposing portion 611a and the end face of the belt 9 is in contact with the spring 614a and 614b And the belt 9 presses the movable member 611 in the direction of the arrow M1 while resisting the pressing force.

For example, when the belt 9 is moved toward the movable member 611, for example, due to the misalignment between the roller 3 and the belt 9, 611). When the belt 9 is further moved in the lateral direction, the belt 9 presses the movable member against the urging force of the springs 614a and 614b in the direction of the arrow M1, thereby utilizing the force of the lateral movement of the belt So that the movable member 611 is moved.

The convex portion 611b of the movable member 611 moves along the concave portion 612b of the holding member 612 so that the movable member 611 moves in the direction of arrow M2. When the convex portion 611b collides with the end of the concave portion 612b, the movement of the movable member 611 is stopped. 33 (b), the distance from the holding sheet 612a of the holding member 612 to the end surface confronting portion 611a of the movable member 611 is D3 (< D2). The movable member 611 is moved by the distance D4 toward the upstream side of the recording material conveying direction S, as compared with the state shown in Fig. 33 (a).

As described above, when the belt 9 is rotating, the inner surface of the belt 9 is in contact with the inner surface facing portion 611c of the movable member 611. [ 33 (b), when the movable member 611 moves toward the upstream side of the recording material conveying direction S, the inner surface facing portion 611c presses the inner surface of the belt 9, As a result, the end of the belt on the side of the correction mechanism 610L moves toward the upstream side of the recording material conveying direction S. On the other hand, the correcting mechanism 610R on the opposite side of the correcting mechanism 610L in the longitudinal direction of the heater is not pressed by the end face of the belt 9, so that the movable member of the correcting mechanism 610R does not move.

When the moving direction of the belt 9 is the opposite direction, that is, when the belt collides with the correcting mechanism 610R, only the movable member in the correcting mechanism 610R moves to the upstream side of the recording material conveying direction S Lt; / RTI &gt; By this movement, the end of the belt on the side of the correction mechanism 610R moves toward the upstream side of the recording material conveying direction S.

In this way, when the belt 9 is laterally moved in the longitudinal direction of the heater (i.e., the direction of the busbars of the belt) and collides with one of the corresponding correction mechanisms 610R and 610L, Only the end portion of the recording medium 9 is urged toward the upstream side in the recording material conveying direction. With this principle, the alignment of the belt 9 with respect to the roller 3 is changed, the orientation of the belt is corrected, and the direction in which the belt is separated from the movable member (that is, The force applied to the end face of the belt 9 is suppressed. Thus, breakage of the belt can be suppressed. As described above, the movable member 611 is pressed by the springs 614a and 614b. 33 (b), when the belt 9 is moved in the direction opposite to the direction of the arrow M1, the movable member 611 moves from the position shown in Fig. 33 (a) Is returned to a position between the positions shown in (a) and (b) of Fig.

34 (a) and (b), the principle of reducing the stress applied to the end face of the belt 9 will be further described. 34 (a) and 34 (b) are views showing the heating unit 2 and the roller 3 viewed from the side of the belt 9, respectively. Figure 34 (a) shows a state in which the belt is moved in the lateral direction. 34 (b) shows a state in which the orientation of the belt 9 is corrected.

Generally, the lateral movement of the belt 9 in the direction of the busbars is caused by the misalignment of the roller 3 and the belt 9. 34 (a) shows a state in which the roller 3 and the belt 9 are misaligned with respect to each other. 34A shows that the belt end on the side of the correcting mechanism 610R is inclined toward the downstream side of the recording material conveying direction S and the belt end on the side of the correcting mechanism 610L is located on the upstream side of the recording material conveying direction S As shown in Fig. The force F is applied to the belt 9 by the rotation of the roller 3, as shown in Fig. 34 (a). The force F can be decomposed into the force Fl in the direction of the busbars of the belt 9 and the force F2 in the direction orthogonal to the direction of the busbars. The belt 9 is moved laterally toward the correcting mechanism 610R by the force F1. When the belt 9 presses the movable member in contact with the movable member 611 of the correcting mechanism 610R, the movable member 611 is guided by the holding member 612 and moves toward the upstream side of the recording material conveying direction S do. The movement of the movable member 611 corrects the orientation of the belt 9 as shown in Fig. 34 (b) based on the above-described principle. Since the roller 3 and the belt 9 are no longer misaligned, the angle between the force F and the direction of the busbars of the belt 9 is changed. As a result, the force F1 is reduced, and the stress applied to the end face of the belt 9 is also reduced.

As described above, the stress applied to the end surface of the belt 9 can be reduced, so that the abrasion of the end surface of the belt 9 can be suppressed.

When the belt 9 is laterally moved due to the misalignment between the roller 3 and the belt 9, the belt end portion of the laterally shifted side is inclined downward in the sheet conveying direction. Thereafter, when the belt 9 collides with the end surface confronting portion 611a of the movable member 611, as shown in Fig. 35, the belt 9 is moved in the sheet conveying direction among the end surface confronting portions 611a And collides with the region on the upstream side. When the belt 9 collides with the end face opposing portion 611a, the movable member 611 collides with the concave portion 612b at the point Q with the point P of the convex portion 611b as a fulcrum (In the direction of the arrow RO shown in the figure) to rotate the convex portion 611b. Therefore, the convex portion 611b of the movable member and the concave portion 612b of the holding member are jammed, and as a result, smooth movement of the movable member is prevented.

In the present embodiment, the coil springs 614a and 614b are entirely in contact with the belt end face of the movable member 611 in a state in which the movable member 611 is not pressed by the belt 9 (See Fig. 32). Therefore, with respect to the moment in the direction of the arrow RO, the force CF of the spring 614a becomes a reaction force and functions to reduce the force applied to each of the point P and the point Q. [ Thereby, the movable member 611 can smoothly move along the concave portion 612b of the holding member 612. [ The coil spring may be arranged so that the center position 614X of the coil spring is located in an area outside the area CA.

While the belt 9 is moved in the lateral direction, the force of the spring 614a acts as a reaction force of a moment in the direction of the arrow RO. This is because the spring 614a is disposed outside the belt contact area CA of the end surface facing portion (i.e., upstream side in the sheet conveying direction). The magnitude of the reaction force generated by the compression of the spring 614a is equal to the magnitude of the force that presses the end face opposing portion 611a caused by the lateral movement of the belt 9. The distance L2 to the spring 614a is longer than the distance L1 from the fulcrum P to the point where the end face opposing portion 611a contacts the belt 9. [ Therefore, the force CF effectively works to cancel the moment in the direction of the arrow RO.

When the belt 9 is inclined in the direction opposite to the direction shown in Fig. 35, the spring 614b works in the same way as the spring 614a and acts as a reaction force against the moment in the direction opposite to the direction of the arrow RO, The member 611 smoothly guides and moves.

In the above embodiment, the correction mechanism is provided at both opposite ends of the belt. However, the above-described correction mechanism can be provided only on the side where the belt is moved in the lateral direction. In this case, It is set in advance. In the present embodiment, it is assumed that the length of the belt is shorter than the span between the two movable members. However, the length of the belt may be approximately equal to the span between the two movable members, that is, both ends of the belt may always be in contact with the two movable members.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (52)

A fixing device for fixing an image formed on a recording material to a recording material,
A tubular flexible rotating body rotating while contacting with a recording material on which an image is formed,
And an inner surface opposed portion opposed to the inner surface of the rotating body at an end portion in the direction of the busbar of the rotating body,
And the inner surface facing portion moves toward the upstream in the carrying direction of the recording material in accordance with the lateral movement of the rotating body in the direction of the bus bar. The method according to claim 1,
And the inner surface of the rotating body is pressed by the inner surface opposed portion by the movement of the inner surface facing portion in the conveying direction upstream. 3. The method of claim 2,
Further comprising an end face opposing portion facing the end face of the rotating body,
And the inner surface opposed portion moves upstream in the conveying direction by a force that the rotating body presses the end surface opposed portion when the rotating body moves in the lateral direction and the rotating body presses the end surface opposed portion. 3. The method of claim 2,
A sensor for detecting a lateral movement of the rotary body in the direction of the bus bar,
Further comprising a driving portion for moving the inner surface facing portion,
And when the sensor detects a lateral movement of the rotator in the direction of the bus bar, the driving unit moves the inner surface facing portion in the conveying direction upstream. 3. The method of claim 2,
Further comprising a holding member for movably holding the inner surface facing portion,
Wherein the holding member includes a guide portion for guiding the inner surface facing portion to move upstream in the conveying direction. 6. The method of claim 5,
And the inner surface facing portion moves in parallel with the carrying direction. 6. The method of claim 5,
A stay extending through the cylinder of the rotary body in the direction of the busbar of the rotary body,
A frame on which the stay and the holding member are mounted,
Further comprising a first pressing member for pressing the stay and the holding member mounted on the frame,
And a fixing nip portion for conveying the recording material therebetween is formed by the force of the first pressing member. 8. The method of claim 7,
Wherein the number of the inner surface opposed portions is two and the two inner surface opposed portions are provided at positions opposite to the inner surface of both ends in the direction of the busbars of the rotator. 9. The method of claim 8,
And the other inner side facing portion moves to the downstream side in the conveying direction of the recording material in cooperation with the movement of one inner side facing portion when the inner surface facing portion of one side moves to the upstream side in the carrying direction, Further comprising: The method of claim 3,
Wherein the inner surface opposed portion and the end surface opposed portion are integral parts and form a movable member. 11. The method of claim 10,
A holding member for movably holding the movable member;
And a second pressing member provided between the holding member and the movable member, the second pressing member pressing the movable member to return the rotating body to the lateral movement of the rotating body. 12. The method of claim 11,
Further comprising a tilt restricting mechanism for restricting a tilt of the movable member. 13. The method of claim 12,
Wherein the inclination regulating mechanism includes a first engaging portion provided on the movable member and a second engaging portion provided on the holding member to engage with the first engaging portion. 14. The method of claim 13,
Wherein the first engaging portion is provided at the end face opposing portion. 13. The method of claim 12,
A stay extending through the cylinder of the rotary body in the direction of the busbar of the rotary body,
A frame on which the stay and the holding member are mounted,
Further comprising a first pressing member for pressing the stay and the holding member mounted on the frame,
A fixing nip portion for carrying the recording material therebetween is formed by the force of the first pressing member,
Wherein the inclination regulating mechanism includes a first engaging portion provided on the movable member and a second engaging portion provided on the stay and engaged with the first engaging portion. 13. The method of claim 12,
A heater contacting the inner surface of the rotating body to heat the rotating body,
Further comprising a heater holder for holding the heater,
Wherein the inclination regulating mechanism includes a first engaging portion provided on the movable member and a second engaging portion provided on the heater holder and engaging with the first engaging portion. 12. The method of claim 11,
Wherein the holding member includes a guide portion for guiding the movable member in the upstream direction in the conveying direction,
Wherein the second pressing member is provided in a plurality and the plurality of second pressing members presses an area outside the area of the movable member with which the end face of the rotating body contacts. 18. The method of claim 17,
The plurality of second pressing members are coil springs,
Wherein a plurality of said coil springs are disposed so that a center position of at least said coil spring is located in an area outside an area of a movable member with which an end face of said rotator contacts. The method according to claim 1,
Wherein the rotating body does not stretch in a stretched state. 20. The method of claim 19,
A backup unit that contacts the inside of the cylinder of the rotary body along the bus bar direction,
And a roller for forming a fixing nip portion for carrying and supporting the recording material together with the backup unit through the rotating body,
Wherein the rotating body rotates following the rotation of the roller. 21. The method of claim 20,
And a heater for heating the rotating body. 22. The method of claim 21,
And the heater contacts the inner surface of the rotating body. A fixing device for fixing an image formed on a recording material to a recording material,
A tubular flexible rotating body rotating while contacting with a recording material on which an image is formed,
An inner surface opposed portion opposed to an inner surface of the rotating body at an end portion of the rotating body in the direction of the busbars, the movable member facing the end surface of the rotating body in the direction of the busbars of the rotating body; And a movable member including an end face opposing portion facing the end face opposing portion,
The movable member moves toward the upstream side of the recording material in the conveying direction by the force that the rotating body presses the end face opposing portion when the rotating body moves laterally in the direction of the busbars and the rotating body presses the end face opposing portion. Fixing device. 24. The method of claim 23,
And the inner surface of the rotating body is pressed by the inner surface opposed portion by the movement of the movable member in an upstream direction of the conveying direction. 25. The method of claim 24,
Further comprising a holding member for movably holding the movable member,
Wherein the holding member includes a guide portion for guiding the movable member to move upstream in the conveying direction. 26. The method of claim 25,
And the movable member is moved in parallel with the conveying direction. 26. The method of claim 25,
A stay extending through the cylinder of the rotary body in the direction of the busbar of the rotary body,
A frame on which the stay and the holding member are mounted,
Further comprising a first pressing member for pressing the stay and the holding member mounted on the frame,
And a fixing nip portion for conveying the recording material therebetween is formed by the force of the first pressing member. 28. The method of claim 27,
Wherein the number of the movable members is two and the two movable members are provided at positions opposite to the two end faces of the rotator. 29. The method of claim 28,
And the other movable member is moved to the downstream side in the conveying direction of the recording material in association with the movement of one of the movable members when the one movable member moves in the conveying direction upstream, Further comprising: 28. The method of claim 27,
And a second pressing member provided between the holding member and the movable member, the second pressing member pressing the movable member to return the rotating body to the lateral movement of the rotating body. 28. The method of claim 27,
Further comprising a tilt restricting mechanism for restricting a tilt of the movable member. 32. The method of claim 31,
Wherein the inclination regulating mechanism includes a first engaging portion provided on the movable member and a second engaging portion provided on the holding member to engage with the first engaging portion. 33. The method of claim 32,
Wherein the first engaging portion is provided at the end face opposing portion. 32. The method of claim 31,
Wherein the inclination regulating mechanism includes a first engaging portion provided on the movable member and a second engaging portion provided on the stay and engaged with the first engaging portion. 32. The method of claim 31,
A heater contacting the inner surface of the rotating body to heat the rotating body,
Further comprising a heater holder for holding the heater,
Wherein the inclination regulating mechanism includes a first engaging portion provided on the movable member and a second engaging portion provided on the heater holder and engaging with the first engaging portion. 31. The method of claim 30,
Wherein the second pressing member is provided in a plurality and the plurality of second pressing members presses an area outside the area of the movable member with which the end face of the rotating body contacts. 37. The method of claim 36,
The plurality of second pressing members are coil springs,
Wherein a plurality of said coil springs are disposed so that a center position of at least said coil spring is located in a region outside an area of said movable member with which an end face of said rotator contacts. 24. The method of claim 23,
Wherein the rotating body does not stretch in a stretched state. 39. The method of claim 38,
A backup unit that contacts the inside of the cylinder of the rotary body along the bus bar direction,
And a roller for forming a fixing nip portion for carrying the recording material therebetween together with the backup unit through the rotating body,
Wherein the rotating body rotates following the rotation of the roller. 40. The method of claim 39,
And a heater for heating the rotating body. 41. The method of claim 40,
And the heater contacts the inner surface of the rotating body. A fixing device for fixing an image formed on a recording material to a recording material,
A tubular flexible rotating body rotating while contacting with a recording material on which an image is formed,
And an outer surface opposed portion opposed to an outer surface of the rotating body at an end portion in the direction of the busbar of the rotating body,
And the outer surface facing portion moves toward the upstream in the recording material conveying direction in accordance with the lateral movement of the rotating body in the direction of the bus bar. 43. The method of claim 42,
And the outer surface of the rotating body is pressed by the outer surface opposed portion by the movement of the outer surface opposed portion in the upstream direction of the conveying direction. 44. The method of claim 43,
Further comprising an end face opposing portion facing the end face of the rotating body,
And the outer surface opposed portion moves upstream in the conveying direction by a force that the rotating body presses the end surface opposed portion when the rotating body moves in the lateral direction and the rotating body presses the end surface opposed portion. 44. The method of claim 43,
A holding member for movably holding the outer surface facing portion,
A stay extending through the cylinder of the rotary body in the direction of the busbar of the rotary body,
A frame on which the stay and the holding member are mounted,
Further comprising a first pressing member for pressing the stay and the holding member mounted on the frame,
And a fixing nip portion for conveying the recording material therebetween is formed by the force of the first pressing member. 45. The method of claim 44,
And the outer surface facing portion is moved in parallel with the carrying direction. 47. The method of claim 46,
Wherein the plurality of outer surface opposed portions are provided at positions opposite to the outer surfaces of both end portions in the direction of the busbars of the rotator. 45. The method of claim 44,
Wherein the outer surface opposed portion and the end surface opposed portion are integral parts and form a movable member. 43. The method of claim 42,
Wherein the rotating body does not stretch in a stretched state. 50. The method of claim 49,
A backup unit that contacts the inside of the cylinder of the rotary body along the bus bar direction,
And a roller for forming a fixing nip portion for carrying the recording material therebetween together with the backup unit through the rotating body,
Wherein the rotating body rotates following the rotation of the roller. 51. The method of claim 50,
And a heater for heating the rotating body. 52. The method of claim 51,
And the heater contacts the inner surface of the rotating body.

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